Device for protecting a motor vehicle controller against illicit exchange

ABSTRACT

An apparatus for preventing the replacement of a control unit, present in a motor vehicle, by an unauthorized person. The apparatus includes a function-inhibiting device, associated with a connection between the control unit and the connector element of an electrical supply lead, which immobilizes the control unit and the connection element in a predetermined connected position with respect to one another. Disconnection from this connected position without damage is possible only after delivery of an unlocking code to the control unit. If an attempt at forcible disconnection is made, the function-inhibiting device causes an irreversible interruption in the associated connection.

FIELD OF THE INVENTION

The present invention relates to an electronic drive lock.

BACKGROUND INFORMATION

A conventional electronic drive lock is described in German publication“mot”, February 1995, pages 102-106. Such a conventional drive lock isbased on an access device in the form of an ignition key, a handheldtransmitter (or a chip card), a control unit containing the drive lock,and an engine management control unit for controlling a gasoline ordiesel engine. Other functional elements present in the vehicle can alsobe connected to the drive lock control unit, for example the electricfuel pump or the starter. A prerequisite for providing a vehicleequipped with the drive lock as described is that a prescribed unlockingcode should be delivered to the drive lock control unit. Because thevehicle cannot, for this reason, readily be started up by anunauthorized person, the conventional drive lock offers at least someprotection against theft, i.e. the vehicle being driven away. Given theincreasing professionalism of vehicle thieves, however, it isforeseeable that vehicles will be misappropriated by replacing theoriginal, locked drive lock control unit with an unlocked but otherwisefunctionally identical replacement control unit.

Accordingly, it is the object of the invention to indicate a possibilityfor preventing the theft of vehicles by replacing a control unit.

SUMMARY OF THE INVENTION

This object is achieved with a device according to the presentinvention. A replacement protector according to the present inventionconsiderably increases the effort required to steal a vehicle byreplacing a protected control unit. In the event of forcible severing ofa connection, secured according to the present invention, between theelectrical supply lead and control unit, the electrical supply lead mustbe properly equipped with a connector element. For a vehicle thief, theeffort to remove such replacement protector is cost-intensive and mostof all time-consuming. For a legitimate user, on the other hand, thereplacement protector according to the invention involves no additionaleffort when removing a protected control unit. It is advantageous,according to the present invention to provide a supply lead and acontrol unit with respect to one another in such a way that even whenconnected, a slight relative movement is possible. This makes itpossible to eliminate any contact problems between supply lead andcontrol unit by gently jiggling the connection, with no need to unlockthe control unit for the purpose.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a drive lock according to the present invention.

FIG. 2 shows a control unit of the drive lock illustrated in FIG. 1 withconnected electrical supply leads.

FIG. 3 shows a combination of the contact spring, connector pin, andlever with retaining pin for the control unit illustrated in FIG. 2.

FIG. 4 schematically illustrates exemplary parts of a control unit and aconnector element according to the present invention including a fuse, acircuit breaker and a battery.

FIG. 5 schematically illustrates an exemplary electrical transmittercircuit 52 according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows, exemplary, a drive lock for motor vehicles which is lockedand unlocked using of a magnetic card 33. The code stored on magneticcard 33 is read by a card reader 32 which is connected via an electricalconnection 21 to a drive lock control unit 30. Connected downstream fromthis via a further electrical connection 21 is an engine control unit 31which controls, among other things, ignition system 34 and fuelinjection system 35. Also connected to drive lock control unit 30 isstarter 36 and, if necessary, other control units present in thevehicle. Control units 31 and 36 are enabled, thus making it possible tostart up the vehicle, only if a correct unlocking code has beendelivered to drive lock control unit 30 by the use of an authorizedmagnetic card 33. The use of a magnetic card as the code carrier isexemplary only; any other conventional code delivery system can ofcourse also be used. Other such systems may also include the commonsystems which operate in non-contact fashion. A more detailed diagram ofthe general layout of a conventional drive unit is provided in thepublication ‘mot’.

FIG. 2 shows the layout of a connection between one or more electricalconnections 21 and a control unit 40. The control unit 40 can be drivelock control unit 30, card reader 32, engine control unit 31, or starter36. The control unit includes a housing 10 in which an electroniccircuit 14 is arranged. An exemplary illustration of electronic circuit14 is shown in FIG. 2 having the form of a circuit board. Located on oneside of housing 10 is a connector receptacle 15 in which one or moreelectrical connector pins 16 are arranged, which lead inside housing 10to circuit 14. Also located in control unit housing 10 is an actuator 11which can be actuated using an electrical signal delivered externally.Actuator 11 may be advantageously configured as part of electroniccircuit 14. Actuator 11 moves one end of a lever 12 that is rotatableabout a bearing shaft 17, the other end of Lever 12 being arrangedoutside housing 10 and inside connector receptacle 15. At the externalend, lever 12 has a retaining pin 13. Bearing shaft 17 is in turnmounted in connector receptacle 15 or in housing 10.

Engaging with a precise fit into the connecting device mounted on thecontrol unit, constituted by connector receptacle 15 with connector pins16 as well as levers 12 with retaining pins 13 located therein, is aconnector element 20 to which are guided all the electrical supply leads21 to be connected to electronic circuit 14 arranged in the controlunit. Connector element 20 is made up of a housing which encloses aninterior space 25 in which electrical supply leads 21 end. One connectorside 24 of the housing of connector element 20 is configured to fitprecisely onto the contour of connector receptacle 15 mounted on thecontrol unit. Located in connector side 24 of connector element 20 arerecesses in which contact springs 22 are arranged, matched in terms ofphysical position to connector pins 16 on the control unit side. When aconnection is made between connector element 20 and control unit 40,these springs coact with connector pins 16. Inside cavity 25, contactsprings 22 extend into connector lugs 26, to each of which, as a rule,one electrical supply lead is guided. A defined break point 23 isconfigured in each case between connector lug 26 and the internal end ofa contact spring 22. This break point can be implemented, for example,by reducing the cross section of connector lug 26 at one point, or byusing a brittle, easily breakable material. At least some of contactsprings 22 also have, in connector region 24, an opening 27 (shown inFIG. 3) whose axis lies substantially perpendicular to the directionalong which contact spring 22 and connector pin 16 coact. Opening 27 isarranged so that when connector element 20 and control unit 40 assume apredetermined position with respect to one another, lever 12 withretaining pin 13 can be pivoted at its tip into opening. In one exampleembodiment of the present invention, an electrical transmitter circuit52 (FIG. 5) generates an acknowledgment signal when the predeterminedconnected position is established.

It is also advantageous that, opening 27 has the shape of a holeelongated along the effective direction of the connection betweenconnector element 20 and control unit 40. Control unit 40 (with housing10) can, as a result, be moved slightly with respect to one another evenif lever 12 with retaining pin 13 is engaged in opening 27. Thus, ifthere is no electrical contact between a spring contact 22 and aconnector pin 16, an attempt can first be made, by gently jiggling theconnection at connector element 20 of control unit 40, to re-establishcontact.

The arrangement described above can be is utilized as follows. At eachtermination of a vehicle operation that took place after priorauthorized startup, a signal is generated from card reader 32 or drivelock control unit 30 which authorizes actuator 11 to pivot lever 12 withretaining pin 13 into opening 27 in contact spring 22 or connector pin16. The coaction of retaining pin 13, lever 12, and the contact springsis illustrated in FIG. 3. If, in this state, connector element 20 andcontrol unit 40 are forcibly disconnected, defined break point 23 inconnector element 20 breaks, causing contact springs 22 to be torn outof their mount in connector element 20, and the associated electricalconnection 21 to be interrupted. A different control unit can no longerbe connected to the vehicle by way of connector element 20 that has beendamaged in this fashion.

If, however, a control unit is to be removed or replaced with theconsent of the legitimate owner, for example in the event of a defect orin the context of maintenance, a defined unlocking code signal is to bedelivered for this purpose to the relevant control unit. This codesignal can be generated only by a legitimate user who is in possessionof the correct magnetic card 33. The code can be generated in variousways; in simple fashion, for example, the code is already located onmagnetic card 33 and can be read out with an additional appropriate cardreader. On the basis of the code signal, actuator 11, even in theshut-down state, pivots lever 12 with retaining pin 13 out of opening27, or causes the lever not to pivot into the opening into the firstplace, whereupon connector element 20 can be disconnected from controlunit 10 without damage.

Retaining the basic conception of securing the connection between theconnector element of an electrical supply lead and a control unit bymeans of a mechanical catch which acts perpendicular to the connectiondirection and can be actuated without damage only with the aid of a codesignal, a plurality of embodiments of the arrangement whose principle isset forth in FIGS. 2 and 3 is possible. This applies, for example, tothe nature and arrangement of actuator 11, the configuration of lever 12with retaining pin 13, the nature and configuration of defined breakpoint 23, or the number of catch devices. Interchanging of functions isalso possible, the actuator being arranged in connector element 20 anddefined break point 23 in control unit 40.

It is also possible to provide electrical retention instead ofmechanical retention using retaining pin 13. For example, as illustratedin FIG. 4, a circuit breaker 44 and a battery 46 to power it can beprovided in control unit 40, and a safety fuse 42 in connector element20. If an unauthorized person attempts forcibly to sever the connectionbetween the connector element and control unit 40, the circuit breakerfeeds a high current into one of electrical connections 16, 21 in theconnector element, which causes the safety fuse to be destroyed.Provision can also be made for the high current fed in by the circuitbreaker to control unit 40 to cause destruction of the accessory poweredby the relevant electrical connection 16, 21, for example an enginespeed sensor.

What is claimed is:
 1. An apparatus for preventing a replacement of acontrol unit situated in a motor vehicle by an unauthorized person,comprising: a securing device controlling a connection between thecontrol unit and a connector element of an electrical supply lead, thesecuring device restraining the connection from being severed andsecuring the control unit to the connector element so that the controlunit maintains a predetermined connected position with respect to theconnector element, wherein the connector element is disengageable fromthe control unit without being damaged only if an unlocking code istransmitted to the control unit.
 2. The apparatus according to claim 1,wherein the securing device irreversibly interrupts an electricalconnection if the connector element is disconnected from the controlunit without the unlocking code being received by the control unit, theelectrical connection including the electrical supply lead.
 3. Anapparatus for preventing a replacement of a control unit situated in amotor vehicle by an unauthorized person, comprising: a securing devicecontrolling a connection between the control unit and a connectorelement of an electrical supply lead, the securing device restrainingthe connection from being severed and securing the control unit to theconnector element so that the control unit maintains a predeterminedconnected position with respect to the connector element, wherein thesecuring device is electrically actuatable.
 4. The apparatus accordingto claim 3, wherein the securing device includes a lever controlled byan electrical actuator to mechanically secure the connector element tothe control unit.
 5. The apparatus according to claim 4, wherein thelever includes a retaining pin to engage a securing opening in theconnection between the control unit and the connector element, thesecuring opening formed by an alignment of openings in the control unitand the connector element, the alignment occurring when the control unitand the connector element are in the predetermined connected position.6. An apparatus for preventing a replacement of a control unit situatedin a motor vehicle by an unauthorized person, comprising: a securingdevice controlling a connection between the control unit and a connectorelement of an electrical supply lead, the securing device restrainingthe connection from being severed and securing the control unit to theconnector element so that the control unit maintains a predeterminedconnected position with respect to the connector element, wherein thesecuring device includes a mechanical retaining device, the mechanicalretaining device, upon electrical actuation, being movable perpendicularto a connection direction of the connector element and perpendicular toa motion direction of the control unit.
 7. An apparatus for preventing areplacement of a control unit situated in a motor vehicle by anunauthorized person, comprising: a securing device controlling aconnection between the control unit and a connector element of anelectrical supply lead, the securing device restraining the connectionfrom being severed and securing the control unit to the connectorelement so that the control unit maintains a predetermined connectedposition with respect to the connector element, wherein the connectorelement is slightly movable with respect to the control unit even whenthe securing device is securing the control unit to the connectorelement.
 8. An apparatus for preventing a replacement of a control unitsituated in a motor vehicle by an unauthorized person, comprising: asecuring device controlling a connection between the control unit and aconnector element of an electrical supply lead, the securing devicerestraining the connection from being severed and securing the controlunit to the connector element so that the control unit maintains apredetermined connected position with respect to the connector element,wherein the control unit is slightly movable with respect to theconnector element even when the securing device is securing the controlunit to the connector element.
 9. An apparatus for preventing areplacement of a control unit situated in a motor vehicle by anunauthorized person, comprising: a securing device controlling aconnection between the control unit and a connector element of anelectrical supply lead, the securing device irreversibly interrupting anelectrical connection if the connector element is disconnected from thecontrol unit without an unlocking code being received by the controlunit, the electrical connection including the electrical supply lead,the securing device including a safety fuse situated in the electricalconnection, the safety fuse being destroyed by a large current generatedin the control unit it the control unit does not receive the unlockingcode before the control unit is disconnected from the connectionelement.
 10. An apparatus for preventing a replacement of a control unitsituated in a motor vehicle by an unauthorized person, comprising: asecuring device controlling a connection between the control unit and aconnector element of an electrical supply lead, the securing devicerestraining the connection from being severed and securing the controlunit to the connector element so that the control unit maintains apredetermined connected position with respect to the connector element,wherein the securing device includes an electrical transmitter circuitgenerating an acknowledgment signal when the predetermined connectedposition is established.